亜鉛センサーCzrAのアロステリック運動のシミュレーション
Dhruva K Chakravorty1, Bing Wang, Chul Won Lee
1Department of Chemistry and the Quantum Theory Project, 2328 New Physics Building, P.O. Box 118435, University of Florida, Gainesville, Florida 32611-8435, USA.
Journal of the American Chemical Society
|October 20, 2011
まとめ
亜鉛がStaphylococcus aureus CzrAに結合すると,構造的なスイッチが発生し,DNA結合が減少する. 分子ダイナミクスシミュレーションは,このアロステリック調節機構を明らかにし,タンパク質の運動運動を強調します.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- コンピュータ生物学 コンピュータ生物学
背景:
- Staphylococcus aureus CzrAは,細胞の金属ホメオスタシスを維持するために不可欠な亜鉛感知トランスクリプション抑制剤です.
- 金属センサタンパク質は,金属イオン結合に起因する形状の変化を通じて細胞プロセスを調節する.
研究 の 目的:
- CzrAにおける亜鉛誘発性アロステリック調節の分子基礎を調査する.
- 亜鉛がCZrAと結合することで生じる形状の変化と自由エネルギー環境を明らかにする.
主な方法:
- クラシック分子動力学 (MD) シミュレーション.
- 量子力学/分子力学 (QM/MM) MDシミュレーション.
- 基本的動力学と相関する運動の分析.
主要な成果:
- シミュレーションでは,亜鉛 (II) 結合時にCrAの"閉"から"開"の形状転換を捉えました.
- 亜鉛結合は,全局的形状サンプリングを制限し,DNAインターフェースの静電電位を変化させます.
- His97とαRヘリックスを含む水素結合経路は,アロステル信号伝送の鍵として特定されました.
結論:
- 金属イオン結合は,CzrAの四次構造変化の主な原動力である.
- タンパク質の動きは,CrAのアロステリック調節機構にとって不可欠である.
- これらの発見は,CzrAの機能と金属ホメオスタシスに関する分子レベルの洞察を提供します.
関連する概念動画
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
01:19Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
01:08Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
01:08Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...